Allowed memory size of 134217728 bytes exhausted (tried to allocate 20971520 bytes) - Laravel excel

I have a file and, there are a lot of empty columns and rows, and I want to remove those and only keep those rows and columns which are needed.

It was working fine, until I got this file. It is throwing allowed memory size exceeded issue.

Here is the code:

public function formatCSV(Request $request){
    $data = [
        'file_name' =>$request->filename,
        'header_row' => $request->header_row,
    ];
    return Excel::download(new ExportFormattedCSV($data), $request->filename);
}

and this ExportFormattedCSV is:

<?php


namespace App\Exports;

use App\Imports\FormatCSV;
use Maatwebsite\Excel\Concerns\FromArray;
use Excel;
use Maatwebsite\Excel\Concerns\WithEvents;
use Maatwebsite\Excel\Events\AfterSheet;
use Maatwebsite\Excel\Concerns\RegistersEventListeners;

class ExportFormattedCSV implements FromArray,WithEvents
{
    use RegistersEventListeners;
    protected $data;

    public function __construct(array $data)
    {
        $this->data = $data;
    }
    public function array(): array
    {
        $path = storage_path('app/files/scrubber/') . $this->data['file_name'];
        $arr = Excel::toArray(new FormatCSV(), $path);
        $arr = array_shift($arr);

        //header is fixed at 7 (although it may seems 10)
        $arr = array_slice($arr, 7);
        array_pop($arr);
        array_pop($arr);

        $rec_arr = $empty_col = array();
        $empty_col_checked = false;
        foreach ($arr as $ak=>$av){
                if(count(array_filter($av)) != 0){
                    if(!$empty_col_checked){
                        foreach($av as $k => $v){
                            if($v == ''){
                                $empty_col[] = $k;
                            }
                        }
                        $empty_col_checked = true;
                    }
                    $rec_arr[] = $av;
                }
        }

        foreach($empty_col as $ek => $ev){
            if(empty( array_filter(array_column($rec_arr,$ev))) )
            {
                foreach($rec_arr as &$item) {
                    unset($item[$ev]);
                }
                unset($item);
            }
        }

        $pre_val = '';
        $format_header = true;

        foreach ($rec_arr as $ak => $av) {
            foreach ($av as $k => $v) {
                if($ak === 0){
                    if($k === 18){
                        if(stripos($v, 'unit') !== false && stripos($v, 'sqft') !== false){
                            $unit_col = $k;
                        }
                    }
                }

                if ($v == '' && $k == 0) {
                    $rec_arr[$ak][$k] = $pre_val;
                } elseif ($k == 0){
                    $pre_val = $v;
                }

                if(isset($unit_col)){
                    if ($v == '' && $k == $unit_col) {
                        $rec_arr[$ak][$k] = $pre_sqft;
                    } elseif ($k == $unit_col){
                        $pre_sqft = $v;
                    }
                }

                if($format_header){
                    $rec_arr[$ak][$k] = trim(preg_replace('/\s+/', ' ', $v));;
                }
            }
            if($rec_arr[0][45] != "" && $rec_arr[0][44] == ""){
                $rec_arr[0][44] =  trim($rec_arr[0][45]);
                $rec_arr[0][45] = "";
            }
            $format_header = false;
        }

        return $rec_arr;
    }

    public static function afterSheet(AfterSheet $event)
    {
        $active_sheet = $event->sheet->getDelegate();
        $centered_text = [
            'alignment' => [
                'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER, 'vertical' => \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER
            ]
        ];
        $active_sheet->getParent()->getDefaultStyle()->applyFromArray($centered_text);

    }
}

and that FormatCSV is pretty much empty and looks like this:

<?php

namespace App\Imports;

use Illuminate\Support\Collection;
use Maatwebsite\Excel\Concerns\ToCollection;

class FormatCSV implements ToCollection
{

    public function collection(Collection $rows)
    {
        foreach ($rows as $row)
        {

        }
    }
}

Basically, it seems to be throwing the error at this line:

$arr = Excel::toArray(new FormatCSV(), $path);

I have also tried with queue by implementing ShouldQueue, but this is storing empty file with no data at all.

Also, the file doesn't have much rows its just about 7000 rows.

Could I be doing anything wrong? Why its showing blank with queue? With queue, I am just implementing that ShouldQueue and calling that export class as:

Excel::store(new ExportFormattedCSV($data),$data['file_name']);