Growing bamboo commercially could create biofuel possibilities for commercial power generation and serve to sequestrate a percentage of the carbon emitted by the same power generation facilities, says Africa-focused bamboo technology company Afribam.
Afribam director Adrian Sutton tells Engineering News there is a lot of unexplored potential for bamboo as a biomass fuel, and it can be produced and used in power stations as an alternative or supplement to coal.
Using bamboo in such an application requires it to be planted in “great quantities”, he says, adding that a lead time must be factored into the equation when planting new crops. However, Sutton points out that, once a commercial-scale bamboo plantation reaches maturity (within about seven years), numerous yields can be derived from one plantation, as only about 30% of the crop is harvested, leaving the remaining crop in place to grow and be harvested when it reaches appropriate volumes.
Timber, for example, requires clear cutting, with the bulk of each tree harvested, leaving only a stump behind and requiring the replanting of new trees once harvesting is complete.
Further, once the bamboo crop reaches maturity and regardless of harvesting patterns, the in-ground crop will serve as carbon sequestration, removing a significant volume of carbon emitted by a fuel-burning power station.
Sutton highlights that another important advantage of bamboo is the low costs of planting and maintaining such a plantation, compared with alternatives such as timber. “Because of the plant density, and bamboo longevity of up to 120 years, the costs of setting up and administering the plantation are up to 20 times less than the costs of a timber plantation.”
Used as a biomass fuel, bamboo’s calorific value is comparable with regular timber and is much easier to harvest, says Sutton, adding that bamboo can be harvested using manual labour and light tools, thereby empowering local communities and individuals that would otherwise not have the opportunity to provide combustible material for commercial power stations and derive an income.
To convert raw bamboo into a combustion-ready fuel requires its being processed through a densification and torrefaction method, and turning it into a pellet or chip format, which can be fed into a boiler system. The torrefied format renders the bamboo biomass to no longer be susceptible to moisture or degradation.
Ideally, he says the power station using bamboo biomass fuel would need to be in close proximity to the facility that converts the raw material into the densified format.