CO-PRODUCTION OF GREEN, HIGH QUALITY HYDROGEN AND BIO SNG USING ELECTROCHEMICAL HYDROGEN COMPRESSION

摘要

Bio-SNG (Synthetic Natural Gas) is a gas containing mostly CH4, with properties similar to naturalrngas, which can be produced from thermochemical gasification of biomass coupled to subsequent methanation. Due tornits interchangeability with natural gas, SNG can be injected into the existing grid and easily distributed for transport,rnheat, and electricity applications. SNG can also be efficiently converted in a number of proven end-use technologies.rnRecently, ECN has developed and patented a novel technology for the methanation of gas from biomass gasification.rnThe ECN System for MEthanation (ESME) allows the efficient conversion of producer gas from biomass gasificationrnto SNG because the hydrocarbons contained in the producer gas (e.g. benzene, toluene) are not removed butrnconverted, and are thus potentially available to be converted to methane. In October 2014, the main parts of thernsystem were successfully tested downstream atmospheric gasification in a 500-hour experiment. The results were anrnimportant step for the scale-up of bio-SNG production. Engineering of a 4 MWth bio-SNG pilot plant to be located inrnAlkmaar (the Netherlands) is currently underway. One of the main challenges for bio-SNG is to reduce thernproduction cost in order to come closer to the price level of natural gas. A smart approach to achieve this goal is thernco-production of fuels and chemicals. In this work, co-production of bio-SNG and hydrogen has been evaluated duernto the promising market prospects for renewable hydrogen in fuel-cell (automotive/stationary) applications as wellrnhydrogen for (glass, steel, petrochemical) industry. The recovery of hydrogen from biomass gasification producer gasrnis an attractive option for the production of renewable hydrogen from biomass. For this, novel technologies for thernseparation of hydrogen from producer gas are required. The Electrochemical Hydrogen Compression (EHC)rntechnology developed by HyET can selectively extract high-purity (> 99.9%), high-pressure (> 20 MPa), fuel-cellrngrade hydrogen from producer gas. The integration of ECN and HyET technology leads to a reduction of the bio-rnSNG yield, but with similar or higher overall energy efficiency and higher total value of the products, thus loweringrnthe overall cost of bio-SNG production. Within the ‘PurifHy’ project, the concept of co-production of hydrogen fromrnSNG combining the ESME bio-SNG process and the EHC technology has been proven at lab scale. This paper showsrnthe main results obtained within the project and includes an economic outlook for a full scale application.