Flammability of Peat Investigation Progression update

Aims: Our aim has been to analyse the flammability of different peats as they dry out, simulating what might happen outside. We are interested in the following questions: a) How easily does the peat catch fire as it dries (eg does it become a fire hazard?) b) How much water does the peat have to lose by evaporation before the top surface becomes dry enough to ignite easily? c) What methods of ignition (spark, cigarette butt, flame) are most likely to start the peat burning? d) Could there be a link between the percentage by mass of elements commonly found in organic compounds (C,H and possibly O) in the peat, and its readiness to catch fire. e) Are different brands of peat more susceptible to ignition than others, and why might this be?

Method Week 1: We created 2 groups of peat, 1 control group and 1 active group, calculated the mass of peat in each and placed them in a sealed glass desiccator with the drying agent silica to begin the desiccation process under controlled conditions Active group Each week we weighed out a small quantity of peat into an evaporating dish and tried to ignite the peat using a variety of methods including: A direct flame (Lighter/burning item), a spark (Electrical fault) and an ember from a splint (Cigarette butt) We then recorded whether the peat had been ignited, smoked or nothing occurred. We decided to record it as a “successful combustion” if it at least smouldered for 30 seconds or more. Control group Each week we weighed the evaporating dish and noted the change in mass of peat and therefore water lost. This group was not burnt so any changes in mass would be entirely due to loss of water.

Temperature and humidity compared

Our raw findings with annotations Peat flammability data (live samples tested for combustion) Combustion method if successful - smouldering for more than 30s - additional comments Peat A Direct flame Direct flame + ash Direct flame + ash + water uptake Direct flame <1 min Peat B Direct flame + ash + constant mass Water uptake, no combustion Direct flame (ongoing) Peat C Direct flame <1min Peat D Direct flame <1min Peat E Approximate time-line: March April May June July

Limitations Irregular measurements due to mutliple commitments of students and teachers, however we did do one at least once a month to allow for seasonal weather fluctuations Would like the investigate the chemical composition of the peat to predict flammability based on percentage of organic matter as opposed to manufacturer-added fertiliser elements such as N, P or K Did not record humidity, and historic humidity data hard to come by apart from “it was muggy last week, wasn’t it?” Each sample used for testing the flammability wasn’t equal in terms of composition or physical consistency throughout the original sack of compost from that brand Didn’t have any standard conditions or a standard amount when testing each of the samples The methods used to create a spark and hot ashes may have a different effect on the flammability and not be representative of how the fire started at the nursery Was the dessicator equivalent to a plant pot being left outside during an extended spell of dry and hot weather? Does peat actually ignite in the classical “catching fire” sense or does it need to slowly heat up over several hours (difficult to test) and then ignite? The time of day of the nursery fire raises this question

Possible further investigations We had a limited amount of time on this research and feel that there are other factors that could affect the flammability. Record the composition of each compost and using this to see if there is a certain material causing flammability, as we found that the sticks and twigs present in the compost would burn Seeing if other materials such as dead plant material effects the flammability of peat due to trapped air pockets or chemical composition Using different samples of compost and using a peat mixture at different concentrations to see if the concentration effects flammability (mixing with regular soil or sand) Repeating this research to see if similar results are collected on the samples, to find a correlation between certain composts, then investigate into why these types were more flammable, scrutinising their results and their composition