Adding gas from biomass to the gas grid - SGC

In the gas production process the input and output is to be compared. Care should be taken for theaddition of energy to maintain the gasification. The cleaning of the gas also requires energy and isoften included in the gas production subsystem. The potential for the balance of plant depends onthe gas production process. Some gasification processes produce heat, others use heat.Subsystem: upgrading and conversionThis subsystem can include completely different technologies, including boilers, generators and gasconversion units. Also here input and output are to be compared. Some conversion processesproduce waste heat, which can be used in the balance of plant. The production of heat should beconsidered as lost energy unless useful application within or outside the process is found.Subsystem: distributionEnergy is not utilised at the location. Care should be taken for the often considerable losses indistribution networks. The distribution of gas requires compression, electricity has ohmic losses andheat transport suffers considerable heat losses. Due to relatively high losses, heat can only beefficiently distributed over short distances. Electricity and gas can be distributed over largerdistances with small losses of energy. On short distances all energy carriers are acceptable, onmedium distances electricity and gas perform well and at the long distance gas is the only efficientand affordable mean of energy distribution. Long distance transport of gas requires compression tohigh pressure or liquefaction.Subsystem: utilisationThe utilisation of energy is an important item in selection of the preferred energy carrier. Electricityis perfect since it can perform all user functions as the provision of power, heating and coolingefficiently. Transport by electrical vehicles is possible but suffers to capacity limitations. The onlydrawback is the lack of buffering potential. Electricity is to be used when produced. Gas is secondbest. Utilisation for all purposes is possible with high efficiency, but the utilisation equipment is oftenmore complex than the electrical counter part. Storage of gas is very well possible, enabling fullutilisation of all energy produced from biomass. Heat is a restricted energy carrier. It can be used forheating and with a low efficiency also for cooling. Conversion of low-grade heat to electricity has avery low efficiency. Storage of heat for a couple of days is feasible, but heat produced in summerwill be nearly without use.page: 11