Biogas Transport and Distribution Evaluating Alternatives and Cost Efficiency

Transcription

1 Biogas Transport and Distribution Evaluating Alternatives and Cost Efficiency Bergen 20th August 2012 This publication has been produced with the assistance of the European Union ( The content of this publication is the sole responsibility of Baltic Biogas Bus and can in no way be taken to reflect the views of the European Union.

2 The Baltic Biogas Bus project will prepare for and increase the use of the eco-fuel Biogas in public transport in order to reduce environmental impact from traffic and make the Baltic region a better place to live, work and invest in. The Baltic Biogas Bus project is supported by the EU, is part of the Baltic Sea Region programme and includes cities, counties and companies within the Baltic region. Author: Tor Ivar Hetland, Gasnor and Stein Bjørlykke, HOG Energi Project manager: Nelson Rojas, HOG Energi Project: Baltic Biogas Bus, WP5.4 Date: 20th August 2012 Reviewed by: Anneli Waldén, Stockholm Public Transport Mikołaj Krupiński, Motor Transport Institute 2

3 Summary The distribution of biogas is one of the challenges one has to deal with in areas where population is scarce and natural gas grid do not excist. In this paper we have considered different alternatives of transporting biogas with special emphasis on composite vessels for transport of compressed biogas. These coposite vessels are compared to steel vessels, pipelines and bulk transport of liquified biogas. Two main scenarios are looked into; a bus depot with 50 and one with 100 buses. Transport distance between 20 and 100 km are considered.the analyses show that with such a small amount of gas to transport, pipelines are not competitive unless the transport distance is less than 5 km. Transport cost is lowest when biogas is transported liquified. Transport of compressed biogas in composite vessels is cheaper than in steel vessels when supplying to more than 50 buses more than 40 km away or more than 100 buses 20 km away. For shorter distances or fewer buses, steel vessels are competitive. Cost of liquefaction, cost of upgrading, compression and costs at the bus depot will influence on total costs of the value chain and should there for be included in the analyses of transport solutions. New membrane techniques and upgrading through liquifaction has to be considered in the future when designing infrastructure for biogas transport. 3

4 Table of Contents 1 Introduction CNG trailers LNG trailers Scenario 1, 50 busses Scenario 2, 100 busses Discussion analysis Tables and figures Table 1: Estimated biogas consumption for 50 and 100 buses... 6 Figure 1: Price CNG composite trailers... 7 Figure 2: Price CNG steel trailers... 7 Figure 3: Price LNG trailers... 8 Figure 4: Scenario 1 EUR/Sm3 for 50 buses and different transport alternatives. 10 Figure 5: Scenario 2 EUR/Sm3 for 100 buses and different transport alternatives 11 Figure 6: EUR/Sm3 for 50 and 100 buses and all transport alternatives Table 2: Cryogenic upgrading energy consumption and cost - GtS consept Figure 7: Upgrading cost of different available technologies

5 1 Introduction Increased use of climate neutral biogas as fuel for buses plays an important part in reducing the overall emissions from public transport. The usage and demand of biogas for this purpose is growing rapidly, and the search for the optimal solutions considering production, transportation and usage is being explored. This study aims to map out the most cost efficient way to transport natural/biogas from the production plant to fillings stations. As established infrastructure for natural gas can be used for biogas, the discussion will be done in the light of calculations done for distribution of natural gas. The following discussion will be based on Norwegian traffic regulations, considering allowed length and weight for road transportation. In the following, three alternative ways of transporting will be compared and discussed. 1. CBG (Compressed biogas), steel and composite containers 2. LBG (Liquefied biogas) 3. Pipeline (private/local) Finding the most suitable way of biogas transportation will in most cases be equal to finding the lowest cost alternative. In short this means dividing transportation costs on a certain amount of transported gas to a determined distance. Therefore, the following scenarios will be evaluated. Biogas for 50 buses transported 20, 50 and 100 kilometers Biogas for 100 busses transported 20, 50 and 100 kilometers To determine the needed amount of biogas, consumption per kilometer is stipulated to be 0.6 Sm 3. Furthermore, each bus is estimated to drive km per year. Given these presumptions, approximately needed amount of biogas for 50 buses will be 2.4 mill. Sm 3, and 4.8 mill. Sm 3 for 100 buses. In all its simplicity, the table below indicated needed amount of biogas transported. Seasonal variations, as for instances lower consumption in the summer months, have not been taken into account. 5

6 Table 1: Estimated biogas consumption for 50 and 100 buses Estimated Consumption Number of buses Yearly milage Consumption Sm3 pr. km 0,6 0,6 Source: Gasnor Annual consumption Sm3 Consumption Sm3 pr.month Consumption Sm3 pr week Consumption Sm3 pr 24 h Having determined the amount of biogas to be transported, one has a basis to further evaluate which way of transportation to be used. As mentioned above, in this case we will compare CNG (composite and steel), LNG and by private/local pipeline. 2 CNG trailers There are a number of different alternatives when it comes to CNG trailers. First of all you can choose trailer with composites or steel cylinders, and there is a variety of different capacities. The following table shows different alternatives composite trailers. To indicate the most cost efficient solution, the investment cost has been divided on transportation capacity. For the following comparisons 1 EUR = 8.10 NOK The comparison of the variety of different CNG composite and steel trailers is based on a sample of price indications given by different suppliers. However, other prices from other suppliers might differ from the diagrams shown below. 6

7 Figure 1: Price CNG composite trailers Source: Gasnor 2011 Figure 2: Price CNG steel trailers Source: Gasnor 2011 To make any conclusion based on trailer investments costs and capacities will alone be inconclusive considering the total costs of transporting gas from the upgrading plant to the bus filling station. However, taking these costs into account when calculation the amount of gas needed to be transported will be an important basis for calculating total transportation costs. 7

8 Above we outlined a scenario in which gas for 50 and 100 buses were to be transported 50 and 100 km. In a 24-hour period the 50 buses used approximately Sm3 and 100 buses respectively Sm3 biogas. In the case of 50 buses, the steel trailer 8 might seem to be the smartest choice. On the other hand, the steel trailer 8 may not be the preferred choice when transporting the double amount of gas. Before any further discussions, LNG trailers will be taken into consideration as well as remaining costs related to gas transportation. 3 LNG trailers Figure 3: Price LNG trailers Source: Gasnor 2011 The diagram above indicates that the investment costs divided on the transportation capacity for LNG trailers are considerably lower than for any of the CNG alternatives. In the subsequent section, total transportation costs, as defined below, will be explored related to the scenarios mentioned above. For the purpose of this case study, the following costs are included in the transportation costs; For transporting biogas as CNG or LNG; 1. Investments costs trailer 2. Maintenance costs trailer 3. Cost related to truck and driver Depreciation period for trailer investments, 10 years. Interest, 6 % 8

9 For transporting the biogas by pipeline 1. Trench costs 2. Pipeline 3. Welding costs Depreciation period for pipeline investments, 20 years. Interest, 6 % Based on the assumption that investment costs for trailer (steel or composite) is a major part of the overall costs, the following examples will be used for further evaluations; CNG, Steel cylinders 1. Steel 8 (4 800 Sm3) CNG, Composite cylinders 2. Composite 5 (5 500Sm3) 3. Composite 2 ( Sm3) LNG (29,280 Sm3) Pipeline. Transportation costs for the pipeline alternative will be discussed, and compared with the trailer alternatives in the end. For the comparison of different transportation solutions, it is based on delivery to filling stations with sufficient storage capacity to unload full loaded trailers. For the following evaluation of transportation cost, it is also assumed that buses mainly will be using slow filling over the night. 9

10 4 Scenario 1, 50 busses Figure 4: Scenario 1 EUR/Sm3 for 50 buses and different transport alternatives Source: Gasnor 2011 For the scenario in figure 4 it is presumed that it is possible to supply the bus filling station using one single trailer. However, both composite 5 and the steel alternative will in average have to do 1.5 deliveries each day. In general the LNG alternative is in overall the most cost effective transportation method. On the other hand, this comparison is done without considering LNG production costs or costs related to storage facilities at the gas filling station. Transporting the gas 20 km as CNG, the steel cylinder alternative seems to be the most cost effective. However, the composite 2 alternative becomes more cost efficient from about 50 km. 10

11 5 Scenario 2, 100 busses Figure 5: Scenario 2 EUR/Sm3 for 100 buses and different transport alternatives Source: Gasnor 2011 When needing the double amount of gas transported, one will most likely require two composite 5 and two steel trailers and they will in average have to do more than one delivery each day. For the composite 2 alternative, which can carry Sm3 gas, one trailer should be sufficient delivering in average 1.5 times each day. As the LNG trailer has more extensive transportation capacity, one trailer will be more than enough to ensure adequate supply. As both the amount of gas to be transported and transportation distance increases, will the advantage of transporting the gas as LNG increase accordingly. Among the CNG alternatives, the composite 2 alternative stands out as the best choice for all three distances. Nevertheless, when transporting 20 km the cost difference between the CNG alternatives seem to be marginal. 11

12 Figure 6: EUR/Sm3 for 50 and 100 buses and all transport alternatives Source: Gasnor 2011 In figure 6, costs for transporting biogas by a local pipeline have also been incorporated in the comparison. There are many variables affecting the costs of transporting gas by pipeline, and estimate given can only be an indication. Cost will vary from sparsely populated areas to densely populated areas, ground conditions, rivers/roads/railways to cross etc. In this case the pipeline has been dimensioned for above mentioned consumption. The costs for digging the trench are mostly based on placing the pipeline under sidewalk, and to some extent other areas. As figure 6 indicates, the pipeline alternative will in the case not be competitive. Also when it comes to supplying 100 buses by 20 km pipeline, both the CNG and LNG transportation options seem more suitable. As an digression of the competitiveness of an local pipeline based on the same technical standard as the 20 km pipeline we found that the crossing point with the LNG transport to be at a length of 4,65 km and approximately 6 km respectively 50 and 100 busses. Further that an increase in the gas flow would give the same result as 20 km LNG transport at an multiply factor of 4,3 and 3,3 respectively for 50 and 100 buses. 12

13 6 Discussion analysis Comparing these ways of transporting gas, first and foremost shows that there is no absolute answer to which way gas should be transported. This comparison shows that amount of gas to be transported, and distance most likely will determine preferred choice. For transporting relatively small amounts over short distances, CNG trailer with steel cylinders might be the best choice. Further, as the amounts and distances increases, CNG trailer with composite cylinders assumingly becomes more economically preferable. However, the tables indicate that from 50 km, both trailers with steel and composite cylinders increases more than LNG transportation. To find most efficient way to transport gas, both costs of compressing/liquefying and investments at the filling stations should be considered. One of the most important factors to be considered is the size of production capacity (large-scale manufacturing reducing cost per unit of output). Also the upgrading costs of bio gas were various techniques are common constitute as a important part of total cost. To illustrate this Cryogenic upgrading of bio gas can be mentioned where several participants are developing new technology in the field. In particular we want to mention the Dutch/Swedish company GtS (cooperation between Scandinavian Biogas and Gastreatment Services). In an initial study of comparison finished by Stockholm Vatten in 2009 the GtS process came out with a cost 57 % lower than following participant. This system is still in an early commercial stage, but auspicious. The StG concept based on a cooling process may in a simple description be described as a 4 step process in order to remove different components in the biogas. In the last (4) stage the gas turns liquid. The example in tabular is based on a Nm3/h plant. Investment cost inclusive a 100 m3 LBG tank. 13

14 Table 2: Cryogenic upgrading energy consumption and cost - GtS consept kwh/n m3 Methan e % M.EUR T Kwh/ Sm3 R Step 1-3 0,25 A Step 4 0,15 N Overall loss 0,2 0,5 Compression of upgraded 0,15 biogas 0,20 Estimated investment cost of a container solution* Estimated cost electricity LBNG Estimated yearly cost electricity CBG Estimated yearly hours with maintenance LBNG Estimated yearly hours with maintenance CBG S P 2,8 O R 0,1 T 0,06 h/sm3 0, , Source: Gasnor 2011 * exclusive connection to infrastructure such as water and electricity. EUR 2008 currency in 2010 value. Comparison of different upgrading techniques Until now the most common technologies for biogas upgrading are water scrubbing, pressure swing adsorption, chemical scrubbing, and organic physical scrubbing. Without taking availability of different energy cost a summarize on the cost characteristics has been made in a report of IEA in The characteristics shows that with biogas amounts larger than Nm3/h upgrading cost lie at approximately a cost of 1,2 eurocent pr. kwh. In smaller plants with lesser amounts production costs increase rapidly. (an average production year consisting hours result in a yearly upgraded biogas production at approximately 8 millions Nm3. However as the cryogenic methods shows that the fields of biogas upgrading is developing rapidly and thus the cost development would also be expected to change and likely lead to lower prices. 14

15 Figure 7: Upgrading cost of different available technologies Source: IEA Bioenergy [Energy from biogas and landfill, task 37] by Annelie Petersson og Arthur Wellinger Oct Also in Norway developing cost breaking technology is taking place. At The Department of Chemical Engineering at the Faculty of Natural Sciences and Technology of the Norwegian University of Science and Technology professor May- Britt Hägg has, together with her group fully developed a new membrane technology with a cost reducing method. Commercialism throughout the company MemoAct is to take place these days. 15

16 7 Conclusions Biogas in liquified form is the cheapest transport solution according to the scenarios on this report. It is reasonable to believe that this will be a good option for a high number of projects in the future. Transport of compressed biogas in composite vessels is cheaper than in steel vessels when supplying to more than 50 buses more than 40 km away or more than 100 buses 20 km away. For shorter distances or fewer buses, steel vessels are competitive. Piping of biogas is competitive to liquified biogas transport when transport distance is around 5 km and the number of buses fed are over 50. Piping is competitive at 20 km when feeding at least 250 buses. Cost of liquifaction and cost of upgrading and compression will influence severely on these conclusions. New membrane techniques and upgrading through liquifaction has to be considered in the future when designing new infrastructure for biogas transport. 16